The inventive concept relates generally to electronic memory technologies. More particularly, the inventive concept relates to a memory system comprising a nonvolatile memory device, and related methods of operation.
Semiconductor memory devices can be roughly divided into two categories according to whether they retain stored data when disconnected from power. These categories include volatile memory devices, which lose stored data when disconnected from power, and nonvolatile memory devices, which retain stored data when disconnected from power. Examples of volatile memory devices include dynamic random access memory (DRAM) and static random access memory (SRAM). Examples of nonvolatile memory include mask read only memory (MROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), and electrically erasable programmable read-only memory (EEPROM).
In certain types of nonvolatile memory, such as flash EEPROM, the reliability of memory cells may decrease over time due to limited program or erase endurance. In other words, the memory cells may begin to fail after they have been programmed or erased a certain number of times. Consequently, there is a general need to provide improved techniques to address the effects of limited program or erase endurance.